Mast cell activation syndrome (MCAS) occurs when the body produces a larger number of mast cells than normal. Mast cells release over a 1000 chemical mediators that signal the immune system to react triggering allergic reactions and inflammation. When the body has more mast cells than it should this can lead to severe and frequent issues with seasonal, environmental, medication and food allergies. This can trigger hives, rapid heart rate, rashes, asthma, digestive issues and anxiety among other symptoms. This condition is complex and often goes undiagnosed for years. Treatment must be applied carefully and may require special formulations of medications to reduce reactivity, diet changes and other lifestyle modifications.
For more information on MCAS check out: https://www.aaaai.org/conditions-and-treatments/related-conditions/mcas